Tapered-pile form.



J. STEWART.

TAPERED PILE FORM.

APPLICATION HLED MAY 29. 1912.

Patented Oct. 19, 1915.

COLUMBIA PLANOURAPH CO-IWASHINGTON, D. c

the bottom of this form,

m'rnp stra ns rn'rnnr orrion OHN 'srnwnn'r, or WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE SIMPLEX CONCRETE FILING COMPANY,

OF WASHINGTON, DISTRICT OF: COLUM- BIA, A CORPORATION OF THE DISTRICT OF COLUMBIA.

TAPEBElD-PILE roam.

To all whom it may concern:

Be it known that I, JOHN STEWART,'2L citizen of the United States, residing in Washington, District of Columbia, have invented certain Improvements in Tapered- Pile Forms, of which the following is a specification. One object of this invention is to provide a pile having a lower portion of anniform diameter and a tapered upper portion.

By this invention the pile can be made sufliciently large in diameter at the top to support the base of a column resting upon it and it is. of such a diameter as to serve both as a pile and as a cap.

A further object of the invention is to provide means for forming the pile as fully described hereinafter; reference being ha to the accompanying drawings, in which Figure 1, is a view of the'two pile forms I in section; said pile forms being driven to the depth desired; Fig. 2, is a view showing the main pile form partly drawn and the opening filled with concrete; and Fig. 3, is a view of the completed pile.

Referring to the drawings, A is the main driving form consisting of a cylindrical casing of an even diameter throughout. This casing is of a length equal to the hole to be formed for the reception of the pile. At the bottom of the form A is a band or collar a, firmly secured to the form and at in the present instance, is a castiron point B having a flange against which the driving form rests. his flange is preferably of greater diameter than the driving form so as to produce a hole of a slightly greater diameter in order to Y tween the two forms and a driving blocl: F,

reduce the friction on the driving form.

Surrounding the upper portion of the driving'form, in the present instance, is a tapered form I). This tapered form has a 1 reinforced collar or band cl at its lower end which acts as an abutment for the collar (1 of the main driving form when said form is raised and contacts with the tapered driving form.

' E is the driving head, which rests on both the main form A and the tapered form D. This head has a flange e, which extends heholds them in the proper relative position. On this head is which receives the blow of the pile driver. Both the main driving Patented oct. 19, 1915.

Application filed May .1912. Serial No. 700,482.

form and the tapered form are driven simultaneously to the desired depth, as illustrated in'Fig. 1. The point displaces the ground and compresses it as the pile is driven. The tapered form further compresses the ground at the upper portion of the opening. The main driving form is then partly filled with concrete and drawn as the filling of concrete increases. The tapered form holds the ground while the main form A is withdrawn until it comes in contact with the tapered form, when both forms are withdrawn, and the filling of the opening with concrete is continued until the pile forms are entirely withdrawn; leaving a pile, as illustrated inFig. 3, with a lower,

section of an even diameter throughout and a tapered upper section having a sufficient area at the top to serve the purpose of the ordinary concrete capping used on piles of limited diameters.

It will be understood that the tapered form can be of any length desired; depending considerably upon the ground into which the pile is driven. In some instances, the tube may be long and the amount of taper slight; whereas, in other instances, the diameter of the tapered form may be considerably increased at the top and the length of the form may be shortened.

By making the form in two parts, one of which is tapered, the ground cannot collapse when the main pile form is being withdrawn. The first half of the pull of the main form is through the tapered outer form which supports the ground so that there is no liability of the ground collapsing and mixing with the concrete as it is inserted in the pile.

I claim:

1. The combination of a tapered pile form; a main pile form greater in length than the tapered form and having an external shoulder at its lower end and projecting under the lower end of the tapered form; means for driving said forms into the ground, the shoulder of the main form engaging the tapered form as the main form is withdrawn from the ground.

2. The combination in a pile, of a main pile form of the full depth of the hole to be formed and having an external collar; a detachable point; a tapered form less in length than the main form,'the lower end of said gaging both' forms so that they Will be driven simultaneously into theground, the

5 collar on the, main form engaging the lower portion of thetapered form as it iS-Withdrawn so that the lower POI'tlOIl of the opening canbefilled with. concrete, While the Walls of'the upper portion areret'ained by the tapered form,

main form. v V I 3. The combmatlon 1n a-p1le,'of a maln hollow pile form of the full depth of the 1 hole to be formed; a detachable point at the if Copies of this patent may be obtained for five cents each. by addressing the ".Comn1 i ssioner iof Patents which i's-finally re-j moved on the complete Withdrawal of the I lowerend of said form; a tapered form less in length than the main form; means hereby the tapered form 'will beraisetl by the main form after'it has been withdrawn froni the lower portion of the hole-in the ground so that, on continuing the Withdrawal of V the main form, the tapered form-'Will also be Withdrawn.

1 In 'estimony whereofplhave name to this specification, in the presence of tWo subscribing Witnesses.

VWitnesses: i e FRANK SHUMAN," a 'W. C. BURKHOLDEIR.

Washington, D. C

signed'i y .7 25 j .JQHN sTEW R -i. f 

